Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

A dual-functional Embolization-Visualization System for Fluorescence image-guided Tumor Resection

Rationale: Intraoperative bleeding impairs physicians' ability to visualize the surgical field, leading to increased risk of surgical complications and reduced outcomes. Bleeding is particularly challenging during endoscopic-assisted surgical resection of hypervascular tumors in the head and neck. A tool that controls bleeding while marking tumor margins has the potential to improve gross tumor resection, reduce surgical morbidity, decrease blood loss, shorten procedure time, prevent damage to surrounding tissues, and limit postoperative pain. Herein, we develop and characterize a new system that combines pre-surgical embolization with improved visualization for endoscopic fluorescence image-guided tumor resection. Methods: Silk-elastinlike protein (SELP) polymers were employed as liquid embolic vehicles for delivery of a clinically used near-infrared dye, indocyanine green (ICG). The biophysical properties of SELP, including gelation kinetics, modulus of elasticity, and viscosity, in response to ICG incorporation using rheology, were characterized. ICG release from embolic SELP was modeled in tissue phantoms and via fluorescence imaging. The embolic capability of the SELP-ICG system was then tested in a microfluidic model of tumor vasculature. Lastly, the cytotoxicity of the SELP-ICG system in L-929 fibroblasts and human umbilical vein endothelial cells (HUVEC) was assessed. Results: ICG incorporation into SELP accelerated gelation and increased its modulus of elasticity. The SELP embolic system released 83 ± 8% of the total ICG within 24 hours, matching clinical practice for pre-surgical embolization procedures. Adding ICG to SELP did not reduce injectability, but did improve the gelation kinetics. After simulated embolization, ICG released from SELP in tissue phantoms diffused a sufficient distance to deliver dye throughout a tumor. ICG-loaded SELP was injectable through a clinical 2.3 Fr microcatheter and demonstrated deep penetration into 50-µm microfluidic-simulated blood vessels with durable occlusion. Incorporation of ICG into SELP improved biocompatibility with HUVECs, but had no effect on L-929 cell viability. Principle Conclusions: We report the development and characterization of a new, dual-functional embolization-visualization system for improving fluorescence-imaged endoscopic surgical resection of hypervascular tumors.

Pulse- and field-resolved THz-diagnostics at 4 t h generation lightsources

Multi-color pump-probe techniques utilizing modern accelerator-based 4th generation light sources such as X-ray free electron lasers or superradiant THz facilities have become important science drivers over the past 10 years. In this type of experiments the precise knowledge of the properties of the involved accelerator-based light pulses crucially determines the achievable sensitivity and temporal resolution. In this work we demonstrate and discuss the powerful role pulse- and field-resolved- detection of superradiant THz pulses can play for improving the precision of THz pump - femtosecond laser probe experiments at superradiant THz facilities in particular and at 4th generation light sources in general. The developed diagnostic scheme provides real-time information on the properties of individual pulses from multiple accelerator based THz sources and opens a robust way for sub femtosecond timing. Correlations between amplitude and phase of the pulses emitted from different superradiant THz sources furthermore provide insides into the properties of the driving electron bunches and is of general interest for the ultra-fast diagnostics at 4th generation light sources.

Temperature-responsive silk-elastinlike protein polymer enhancement of intravesical drug delivery of a therapeutic glycosaminoglycan for treatment of interstitial cystitis/painful bladder syndrome

Interstitial cystitis (IC), also known as painful bladder syndrome, is a debilitating chronic condition with many patients failing to respond to current treatment options. Rapid clearance, mucosal coating, and tight epithelium create strong natural barriers that reduce the effectiveness of many pharmacological interventions in the bladder. Intravesical drug delivery (IDD) is the administration of therapeutic compounds or devices to the urinary bladder via a urethral catheter. Previous work in improving IDD for IC has focused on the sustained delivery of analgesics within the bladder and other small molecule drugs which do not address underlying inflammation and bladder damage. Therapeutic glycosaminoglycans (GAG) function by restoring the mucosal barrier within the bladder, promoting healing responses, and preventing irritating solutes from reaching the bladder wall. There is an unmet medical need for a therapy that provides both acute relief of symptoms while alleviating underlying physiological sources of inflammation and promoting healing within the urothelium. Semi-synthetic glycosaminoglycan ethers (SAGE) are an emerging class of therapeutic GAG with intrinsic anti-inflammatory and analgesic properties. To reduce SAGE clearance and enhance its accumulation in the bladder, we developed a silk-elastinlike protein polymer (SELP) based system to enhance SAGE IDD. We evaluated in vitro release kinetics, rheological properties, impact on bladder function, pain response, and bladder inflammation and compared their effectiveness to other temperature-responsive polymers including Poloxamer 407 and poly(lactic-co-glycolic acid)-poly(ethylene glycol). SAGE delivered via SELP-enhanced intravesical delivery substantially improved SAGE accumulation in the urothelium, provided a sustained analgesic effect 24 h after administration, and reduced inflammation.

Clinical relevance of non-tuberculous mycobacteria isolated from respiratory specimens: seven year experience in a UK hospital

The frequency of isolation of non-tuberculous mycobacteria (NTM) species from respiratory specimens is increasing, however the clinical relevance of such identifications vary by mycobacterial species and geographical location. A retrospective study of 853 NTM isolates from respiratory samples from 386 patients over seven years was performed. Clinical records and radiographic information were examined. Clinical significance was assessed by American Thoracic Society diagnostic criteria. 25% of all patients with respiratory isolates met criteria for non-tuberculous mycobacterial pulmonary disease (NTM-PD). Significant symptoms were weight loss, fever, night sweats, productive cough and haemoptysis. HIV co-infection was a significant risk factor for disease. Cavities, nodules and tree-in-bud were significant radiographic findings. Mycobacterium avium complex (MAC) were the dominant species isolated from this patient cohort. Mycobacterium abscessus (M. abscessus) was the species most likely to cause clinically significant disease and be sputum smear positive, thus warranting particular attention.

On-chip THz spectrometer for bunch compression fingerprinting at fourth-generation light sources

The layout of an integrated millimetre-scale on-chip THz spectrometer is presented and its peformance demonstrated. The device is based on eight Schottky-diode detectors which are combined with narrowband THz antennas, thereby enabling the simultaneous detection of eight frequencies in the THz range on one chip. The size of the active detector area matches the focal spot size of superradiant THz radiation utilized in bunch compression monitors of modern linear electron accelerators. The 3 dB bandwidth of the on-chip Schottky-diode detectors is less than 10% of the center frequency and allows pulse-resolved detection at up to 5 GHz repetition rates. The performance of a first prototype device is demonstrated at a repetition rate of 100 kHz at the quasi-cw SRF linear accelerator ELBE operated with electron bunch charges between a few pC and 100 pC.

Towards femtosecond-level intrinsic laser synchronization at fourth generation light sources

In this Letter, the proof of principle for a scheme providing intrinsic femtosecond-level synchronization between an external laser system and fourth generation light sources is presented. The scheme is applicable at any accelerator-based light source that is based on the generation of coherent radiation from ultrashort electron bunches such as superradiant terahertz (THz) facilities or X-FELs. It makes use of a superradiant THz pulse generated by the accelerator as an intrinsically synchronized gate signal for electro-optical slicing. We demonstrate that the scheme enables a reduction of the timing instability by more than 2 orders of magnitude. This demonstration experiment thereby proves that intrinsically synchronized time-resolved experiments utilizing laser and accelerator-based radiation pulses on few tens of femtosecond (fs) to few fs timescales are feasible.

Determination of Plasma Concentration Reference Ranges for Risperidone and Paliperidone

Schizophrenia is a common disease managed by a range of interventions, with the primary treatment being antipsychotic medications (APS). Inadequate response, lack of adherence, and/or adverse events often prevent optimal therapeutic effects or therapeutic efficiency. Monitoring APS plasma concentrations can be used together with a full clinical evaluation to help improve patient care or offer better treatment options for the patient. To enable interpretation of individual risperidone and paliperidone plasma concentrations, we developed "reference ranges," which consider the expected variability in plasma concentrations between subjects across the population, rather than representing a "therapeutic range" that relates to efficacy and/or safety outcomes. The reference ranges were derived from population pharmacokinetic models, which varied based upon administration route, dose, and time after dose. Good agreement between the proposed reference ranges and external data was obtained through graphical and numerical evaluations, indicating they could be reliably used in clinical practice.

Analysis of Affordance, Time, and Adaptation in the Assessment of Industrial Control System Cybersecurity Risk

Industrial control systems increasingly use standard communication protocols and are increasingly connected to public networks-creating substantial cybersecurity risks, especially when used in critical infrastructures such as electricity and water distribution systems. Methods of assessing risk in such systems have recognized for some time the way in which the strategies of potential adversaries and risk managers interact in defining the risk to which such systems are exposed. But it is also important to consider the adaptations of the systems' operators and other legitimate users to risk controls, adaptations that often appear to undermine these controls, or shift the risk from one part of a system to another. Unlike the case with adversarial risk analysis, the adaptations of system users are typically orthogonal to the objective of minimizing or maximizing risk in the system. We argue that this need to analyze potential adaptations to risk controls is true for risk problems more generally, and we develop a framework for incorporating such adaptations into an assessment process. The method is based on the principle of affordances, and we show how this can be incorporated in an iterative procedure based on raising the minimum period of risk materialization above some threshold. We apply the method in a case study of a small European utility provider and discuss the observations arising from this.

Optimizing Antipsychotic Patient Management Using Population Pharmacokinetic Models and Point-of-Care Testing

Schizophrenia is a common disease, characterized by progressive functional decline exacerbated by psychotic relapses that often result from a lack of full adherence to antipsychotic (APS) medication. Although atypical APS medications do not have clear therapeutic windows, as generally required for therapeutic drug monitoring (TDM), measuring APS plasma levels in the context of a population expected range at the point‐of‐care (POC) may provide valuable clinical insights for differentiating lack of efficacy from a lack of adherence to medication.

Challenging hierarchy in healthcare teams - ways to flatten gradients to improve teamwork and patient care

In healthcare, mistakes that are potentially harmful or fatal to patients are often the result of poor communication between members of a team. This is particularly important in high-risk areas such as operating theatres or during any intervention, and the ability to challenge colleagues who are in authority when something does not seem right or is clearly wrong, is crucial. Colleagues in oral and maxillofacial surgery recognised the importance of this as early as 2004, and it is now well known that failure or reluctance to challenge others who might be wrong can severely compromise a patient's safety. The Royal College of Surgeons of Edinburgh runs popular regular courses (Non-technical Skills for Surgeons, NOTSS) that teach how to ensure safety through good communication and teamwork. In this paper we introduce the concept of hierarchical challenge, and discuss models and approaches to address situations when problems arise within a team.

Probing ultra-fast processes with high dynamic range at 4th-generation light sources: Arrival time and intensity binning at unprecedented repetition rates

Understanding dynamics on ultrafast timescales enables unique and new insights into important processes in the materials and life sciences. In this respect, the fundamental pump-probe approach based on ultra-short photon pulses aims at the creation of stroboscopic movies. Performing such experiments at one of the many recently established accelerator-based 4th-generation light sources such as free-electron lasers or superradiant THz sources allows an enormous widening of the accessible parameter space for the excitation and/or probing light pulses. Compared to table-top devices, critical issues of this type of experiment are fluctuations of the timing between the accelerator and external laser systems and intensity instabilities of the accelerator-based photon sources. Existing solutions have so far been only demonstrated at low repetition rates and/or achieved a limited dynamic range in comparison to table-top experiments, while the 4th generation of accelerator-based light sources is based on superconducting radio-frequency technology, which enables operation at MHz or even GHz repetition rates. In this article, we present the successful demonstration of ultra-fast accelerator-laser pump-probe experiments performed at an unprecedentedly high repetition rate in the few-hundred-kHz regime and with a currently achievable optimal time resolution of 13 fs (rms). Our scheme, based on the pulse-resolved detection of multiple beam parameters relevant for the experiment, allows us to achieve an excellent sensitivity in real-world ultra-fast experiments, as demonstrated for the example of THz-field-driven coherent spin precession.

A regional EUS service using a collaborative network

Endoscopic ultrasound (EUS) is increasingly used in the management of hepatobiliary lesions, allowing staging and tissue acquisition. It is operator-dependent, and fine needle aspiration (FNA) of solid lesions provides an auditable standard; high-volume centres have shown excellent results for solid pancreatic lesion FNA with sensitivities of 92%-97%. The British Society of Gastroenterology guidelines stress that clinical quality should determine service provision, with geographical accessibility a secondary consideration. We set up the Wessex EUS network, working from a single hepatobiliary (HPB) pancreatic multidisciplinary team, with EUS provided in four local centres providing agreed standards and audit. Pancreatic solid lesion FNA results showed a pooled sensitivity of 94%, comparable with high-volume single centres. This demonstrates a network with good clinical governance is a plausible solution to providing a specialist service such as EUS and may be a roadmap that other specialist services under pressure could follow.

Information technology in nurse education: a multimedia approach to teaching biological sciences

The School of Health Science at the University of Wales Swansea offers programmes for nurses and other healthcare professionals ranging from pre-registration nursing to post-doctoral studies. Biological science is an important component of the pre-registration programme, the delivery of which has proved to be problematic. Research conducted by the school has identified that a more innovative approach to teaching and learning this subject is required.

There is a growing body of evidence that Multimedia Learning (MML) can enhance the quality of education, supporting or replacing the traditional didactic lecture and providing the student with information and standards of presentation that have never before been available. With this in mind, and responding to the research findings, the school has made a substantial investment in multimedia technology. We have now embarked on a programme to produce and deliver a biological science module for nursing students. If the evaluation of the programme demonstrates sustainable improvements in learning and offers enhanced quality in the delivery of programmes, it is the intention to extrapolate the biological science project to other curriculum subjects.

An update on the latest evidence for managing the clinically negative neck (cN0) in oral squamous cell carcinoma

The single most important prognostic indicator for survival in oral squamous cell carcinoma (OSCC) is the presence of lymph node metastases in the neck. While the treatment of the clinically node positive (cN+) neck is well established, the management of the clinically negative neck (cN0) is controversial. Various strategies have been advocated including close observation including regular ultrasound imaging, elective neck dissection and sentinel lymph node biopsy. Neck dissection surgery is not without potential morbidity with shoulder dysfunction being the main complication. A number of factors are associated with increased risk of neck node metastasis including primary tumour thickness and peri-neural invasion. A recent prospective randomised trial has found survival benefit following neck dissection even in patients with a cN0 neck at presentation. We discuss the latest evidence for managing the cN0 in OSCC and include our own experience on the role of neck dissection in certain cases.

Sentinel lymph node biopsy for head and neck mucosal cancers - an update on the current evidence

Regional metastases are a prominent feature of mucosal-associated head and neck squamous cell carcinomas and are an important prognostic factor. Sentinel lymph node biopsy (SLNB) is one modality that has potential to add to the accuracy of neck staging, although it is currently not used as widely in the head and neck as it is in other areas such as breast cancer. We review the efficacy of SLNB in head and neck mucosal squamous cell carcinomas and provide an overview of current practice and include details of technical advances.

Optical nanoscopy of transient states in condensed matter

Recently, the fundamental and nanoscale understanding of complex phenomena in materials research and the life sciences, witnessed considerable progress. However, elucidating the underlying mechanisms, governed by entangled degrees of freedom such as lattice, spin, orbit, and charge for solids or conformation, electric potentials, and ligands for proteins, has remained challenging. Techniques that allow for distinguishing between different contributions to these processes are hence urgently required. In this paper we demonstrate the application of scattering-type scanning near-field optical microscopy (s-SNOM) as a novel type of nano-probe for tracking transient states of matter. We introduce a sideband-demodulation technique that allows for probing exclusively the stimuli-induced change of near-field optical properties. We exemplify this development by inspecting the decay of an electron-hole plasma generated in SiGe thin films through near-infrared laser pulses. Our approach can universally be applied to optically track ultrafast/-slow processes over the whole spectral range from UV to THz frequencies.

Preoperative neutrophil:lymphocyte and platelet:lymphocyte ratios predict endometrial cancer survival

BACKGROUND

Variations in systemic inflammatory response biomarker levels have been associated with adverse clinical outcome in various malignancies. This study determined the prognostic significance of preoperative neutrophil:lymphocyte (NLR), platelet:lymphocyte (PLR) and monocyte:lymphocyte (MLR) ratios in endometrial cancer.

METHODS

Clinicopathological and 5-year follow-up data were obtained for a retrospective series of surgically treated endometrial cancer patients (n=605). Prognostic significance was determined for overall (OS) and cancer-specific survival (CSS) using Cox proportional hazards models and Kaplan-Meier analysis. Receiver-operator characteristic and log-rank functions were used to optimise cut-offs. NLR, PLR and MLR associations with clinicopathological variables were determined using non-parametric tests.

RESULTS

Applying cut-offs of ⩾2.4 (NLR), ⩾240 (PLR) and ⩾0.19 (MLR), NLR and PLR (but not MLR) had independent prognostic significance. Combining NLR and PLR scores stratified patients into low (NLR-low and PLR-low), intermediate (NLR-high or PLR-high) and high risk (NLR-high and PLR-high) groups: multivariable hazard ratio (HR) 2.51; P<0.001 (OS); HR 2.26; P<0.01 (CSS) for high vs low risk patients. Increased NLR and PLR were most strongly associated with advanced stage (P<0.001), whereas increased MLR was strongly associated with older age (P<0.001).

CONCLUSION

Both NLR and PLR are independent prognostic indicators for endometrial cancer, which can be combined to provide additional patient stratification.

Division of the spinal accessory nerve in the anterior triangle: a prospective clinical study

The anatomical relation between the spinal accessory nerve and internal jugular vein is well documented, but other variants of the nerve, including the contributions of the cervical plexus to supply motor fibres to the trapezius, are less well known. We have previously described an anatomical variant in which the spinal accessory nerve divided before entering the sternocleidomastoid, and the inferior trunk passed directly under it to supply the trapezius. We now present a prospective study of 133 neck dissections (excluding radical dissections) in which a meticulous search was made for the variant in the anterior triangle of the neck during operation. We found it in 3 necks (2%). One of the 3 patients had a bilateral neck dissection but it was found on one side only, and in 2 cases it communicated with the cervical plexus. In all 3, stimulation of the inferior division resulted in contraction of the trapezius while the upper division was found to supply the sternocleidomastoid only. The finding of this variant, which was more common than first thought, highlights the need for meticulous dissection of the nerve before it enters the sternocleidomastoid to ensure that, when present, the inferior branch is preserved to minimise potential postoperative shoulder dysfunction. Further research including a cadaveric study is needed to understand this important variant more fully.

Malignant cutaneous adnexal tumours of the head and neck: an update on management

Adnexal tumours form a heterogeneous group of relatively rare neoplasms. Many of them have a poor prognosis and treatment can sometimes be difficult and controversial. We summarise the latest publications relating to malignant cutaneous adnexal tumours of the head and neck, and give an update on their management. We discuss Merkel cell carcinoma and other rare malignant adnexal tumours including dermatofibrosarcoma protuberans and atypical fibroxanthoma.

Maternal request for caesarean section: audit of a care pathway

This report is based on an audit of the delivery outcome of a specific care pathway for women who had made a maternal request for caesarean section (MRCS). The study took place in a UK inner city National Health Service maternity unit with 6,000 births per year. All 31 multiparous and 16 nulliparous women on the pathway were included. All of the former group had delivered vaginally, all reported having experienced their previous birth as traumatic, and all subsequently delivered vaginally. Of the 16 nulliparous women, six delivered by planned caesarean section; four delivered vaginally; four had an instrumental delivery and two had an emergency caesarean section. A designated multidisciplinary care pathway that incorporates education and support may have the potential to help more women to achieve a normal delivery. More research is needed to assess its potential for reducing unnecessary caesarean deliveries and for improving user experience.

Women's views on and adherence to low-molecular-weight heparin therapy during pregnancy and the puerperium

BACKGROUND

Non-adherence to prescribed medication represents a significant factor associated with treatment failure. Pregnant women identified at risk of venous thromboembolism are increasingly being prescribed low-molecular-weight heparin (LMWH) during pregnancy and the puerperium. It is important to understand women's views on and adherence to LMWH during pregnancy and the puerperium, so that women gain maximum benefit from the treatment.

OBJECTIVES

To monitor women's adherence to enoxaparin, when prescribed during pregnancy and the puerperium, and explore their beliefs about the enoxaparin therapy prescribed.

PATIENTS/METHODS

A prospective cohort study involving 95 nullparous and multiparous women prescribed enoxaparin for recognized antenatal indications. Adherence to enoxaparin was assessed through self-completion of a diary, additionally verified through laboratory tests. An adapted beliefs about medication questionnaire was administered to women during their pregnancy.

RESULTS

Women were highly adherent to enoxaparin: antenatally, mean percentage adherence 97.92%; postnatally, mean percentage adherence 93.37% (paired t-test, P = 0.000). In the cohort of women we followed, their perceived necessity for enoxaparin therapy outweighed any concerns they had regarding enoxaparin antenatally, necessity-concerns differential 2.20. In some women, however, this perceived necessity does decrease postnatally.

CONCLUSIONS

Our results suggest that most women prescribed enoxaparin are highly adherent to their therapy during the antenatal period and that women's antenatal beliefs about enoxaparin are able to predict a decrease in postnatal adherence. Our results have important clinical implications, particularly when women are initiated on LMWH just during the postnatal period.

Surgical treatment for acute spinal cord injury study pilot study #2: evaluation of protocol for decompressive surgery within 8 hours of injury

Acute spinal cord injury (SCI) is a major public health problem for which there is still only limited treatment available. The National Acute Spinal Cord Injury Study-2 (NASCIS-2) and -3 clinical trials demonstrated that the use of acute pharmacotherapy with methylprednisolone can attenuate the secondary injury cascade if administered within 8 hours of acute SCI. However, no trial has been performed to examine whether acute surgical decompressive procedures within this critical 8-hour time window can improve patients' neurological outcome. The purpose of the current prospective Surgical Treatment for Acute Spinal Cord Injury Study (STASCIS) pilot study was to determine the feasibility of obtaining a radiological diagnosis of spinal canal compromise of 25% or more and to perform spinal cord (C3-T1) decompressive procedures by 8 hours postinjury. One of the following three decompressive methods was used: 1) traction alone; 2) traction and surgery; or 3) surgery alone. Twenty-six patients from eight North American centers were entered into the study between 1996 and 1997. Significant difficulties were encountered in many centers in performing immediate magnetic resonance imaging examination in patients with acute SCI. Fewer than 10% of acute cervical SCI patients could be enrolled into this protocol mainly because the combination of the required time for rescue, resuscitation, transport, imaging study, and surgical preparation exceeded the 8-hour injury-to-decompressive surgery window. Eleven patients underwent decompressive procedures initially by being placed in traction at a mean time of 10.9 hours postinjury. Those patients not undergoing this procedure underwent decompressive surgery at a mean time of 40.1 hours. However, the surgical decompressive procedure was completed within 12 hours in seven patients. As a result of these findings, several major changes have been made to the STASCIS protocol for early decompressive therapy.

Search for lepton flavour violation in the eμ continuum with the ATLAS detector in [Formula: see text]pp collisions at the LHC

This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark ([Formula: see text]) in the e±μ∓ continuum using 2.1 fb-1 of data collected by the ATLAS detector in [Formula: see text]pp collisions at the Large Hadron Collider. Data are found to be consistent with the expectation from the Standard Model backgrounds. Limits on R-parity-violating couplings at 95 % C.L. are calculated as a function of the scalar top mass ([Formula: see text]). The upper limits on the production cross section for pp→eμX, through the t-channel exchange of a scalar top quark, ranges from 170 fb for [Formula: see text] to 30 fb for [Formula: see text].

The endoscopically normal colon: when is mapping biopsy histopathologically justifiable?

OBJECTIVE

Mapping biopsy of endoscopically normal colon is a contentious area and generates considerable work for histopathology services. Managing demand for pathological testing is a current healthcare priority. In this retrospective audit, the authors aimed to establish diagnostic yield of mapping biopsy in this specific subgroup and identify situations where practice could be safely streamlined.

DESIGN

Cases were retrieved over a 10-month period. Histopathology results were correlated with relevant endoscopy reports. The data were anonymised and analysed.

SETTING

Department of Cellular Pathology, Southampton General Hospital, UK.

RESULTS

717 cases were retrieved. 308 (43%) cases were reported as endoscopically normal. 278 (90%) cases with endoscopically normal/near normal mucosa showed normal/near normal histology. 30/308 (9.7%) endoscopically normal cases showed pathological abnormalities. 9/308 (2.9%) cases of microscopic colitis were detected. Of the 30 cases with pathological abnormalities, 20 (66.7%) presented with change in bowel habit and 6 (20%) had a pre-existing diagnosis of inflammatory bowel disease.

CONCLUSIONS

Pathological abnormalities in endoscopically normal colon are found most frequently in those who present with change in bowel habit or a known history of inflammatory bowel disease. The authors support biopsy in these individuals and believe that mapping biopsy of endoscopically normal colon in patients referred for other reasons (eg, bright red rectal bleeding or iron deficiency anaemia) should not be performed routinely as diagnostic yields are very low. Guidelines on appropriate use of mapping biopsy in this setting are limited. Streamlining patients based on reason for referral or presenting symptoms may be a useful step towards more effective management of histopathological demand.